Keogh scored the Republic's consolation goal in the loss coming on as a substitute.

"Andy Keogh suffered a knock to the head in training on Saturday," Ireland said in a statement. "He was observed overnight by the FAI medical team and has been ruled unfit to travel to the Faroe Islands this afternoon due to mild concussion."

Keane, having tested his Achilles injury in Malahide on Sunday morning, was among the party that jetted out to Torshavn ahead of Tuesday night's World Cup qualifier, a game Trapattoni has said is a must-win affair.

Trapattoni fastened his seat belt having challenged his players to produce a swift response in the Faroes to get their Group C campaign back on track.

The fallout from the German debacle has left the veteran manager in little doubt that his detractors are growing and that worse could follow if he returns from Torshavn without three points.

Ireland launched their Group C campaign with an unconvincing victory in Kazakhstan last month, and while a lackluster display that night alarmed some, the manager was not among them.

He said: "It was very difficult to recover psychologically after the Euros, but against Kazakhstan, which was not an easy game, and in the friendly against Oman, we had a very important reaction.

"Against Kazakhstan, we played well, not badly. Have you reviewed the DVD? I have reviewed it many, many times and we deserved to win.

"We are not at the top of the world rankings, but we have slowly, slowly recovered the position in the rankings, we have also changed the players and we have a new generation now."

Seamus Coleman and James McCarthy, who started Friday night's game, are perhaps the trailblazers of that new generation, while there are high hopes for Manchester United winger Robbie Brady, whose last-gasp corner after coming on as a substitute led to Keogh's strike.

Just how those youngsters were affected psychologically by a brutally-delivered lesson in international football remains to be seen, and it will be down to Trapattoni and his coaching staff to soothe bruised egos and rebuild confidence ahead of a fixture which will be key to their hopes of mounting a genuine bid to make it to Brazil in 2014.

But Trapattoni sees little point in reading the riot act to his players.

"When you fail, it is no good being angry," he said. "You have to accept Germany were superior.

"I can talk about the little details -- we conceded the first goal because we let a player run in behind. In the past, our players have not made these mistakes, but you can forget this and concede a goal.

"I can't be angry with my players. I have to recharge the batteries because we need their enthusiasm and their energy for the next game on Tuesday."